John Harrington/MedImmune, via PRNewsFoto

More and more, data is becoming a critical tool in honing public health practice to be most beneficial. The CDC’s Advisory Committee on Immunization Practices’ (ACIP’s) recent vote on an interim recommendation for influenza vaccine highlights how and why evaluating public health practices benefits public health policies.

Influenza (flu) causes substantial illness and death every year, but flu vaccines are the first and best way to prevent the disease. Data historically show that people who get vaccinated are, overall, better protected than those who do not; however, flu vaccines can vary in effectiveness from year to year.

For example, the Centers for Disease Control and Prevention (CDC) determined that during 2015-2016, inactivated influenza vaccine (IIV) – the injectable vaccine known as the “flu shot” – demonstrated measurable protection (63%) against the flu virus in children ages 2 to 17 years old. However, the same study found that vaccine effectiveness for live attenuated influenza vaccine (LAIV) – the “nasal spray” vaccine known as FluMist – did not demonstrate a protective benefit for that same age group. Recognizing that LAIV’s low vaccine effectiveness dates back to the 2013-2014 flu season, ACIP voted in favor of an interim recommendation that LAIV, or FluMist, should not be used during the 2016-2017 flu season.

Since flu vaccines prevent flu illnesses, doctor’s visits and hospitalizations, it’s disheartening to see data suggesting that one vaccine is not working as well as expected. But fortunately, flu shots did perform well last season. Across all ages and all flu viruses, vaccine effectiveness for IIV was 49 percent, indicating that millions of people were protected against flu. As such, ACIP continues to recommend annual flu vaccination, with either the inactivated influenza vaccine (IIV) or recombinant influenza vaccine (RIV), for everyone 6 months and older.

Still, ACIP’s vote on the interim recommendation underscores the importance of ongoing efforts to measure and evaluate the effectiveness of public health interventions which can have significant implications for public health policy. In this case, the recommendation may have implications for vaccine providers who have already placed flu vaccine orders for the 2016-2017 season.

Vaccine manufacturers have projected that as many as 171 to 176 million doses of flu vaccine will be made available for the 2016-2017 season. While LAIV accounts for up to 14 million (8%) of that total supply, health officials expect that the supply of IIV for the 2016-2017 season should be sufficient to meet any increase in demand resulting from the ACIP recommendation. Nonetheless, providers may need to order from more than one supplier or purchase a flu vaccine brand other than the one they normally select. Further, providers who have purchased or pre-ordered vaccine will need to consult with the manufacturer or vaccine distributor to ensure their ability to fulfill the order.

While the change in recommendation represents an evidence-based strategy to increase the number of individuals protected from flu, it could have an adverse effect in some localities. According to Tiffany Tate, Executive Director of the Maryland Partnership for Prevention, Inc., Maryland will be “significantly affected” by the ACIP’s recommendation against FluMist. Tate noted that the state immunizes about 100,000 children through school-located clinics, which almost exclusively use the nasal spray vaccine.

It is likely that other states and counties will encounter the same issue, and need a plan to implement alternative vaccination programs that align with the new ACIP recommendation. To assist, NACCHO is issuing a call for experiences and resources from local health departments that conduct school-located influenza vaccination clinics with injectable influenza vaccine. To respond to this call, local health department staff should email [email protected].

In the meantime, local health departments and vaccine providers should begin reviewing existing flu vaccine plans and adjusting those plans as necessary to ensure they are sharing the right recommendations and delivering the most effective vaccines when the 2016-2017 flu season arrives.